Non-clogging aerosol valve

ABSTRACT

An improved aerosol valve intended to prevent clogging with salt crystals provides a high velocity turbulent flow through the stem with interior channels gradually increasing in size. The stem orifices break through into a rectangular portion of the stem flow passage which is the same width as the orifices. The capillary attraction of residue fluid by the narrowly spaced walls prevent clogging of the orifices. The concept further includes a spring cup or valve housing wherein the material gradually expands from a restricted entrance opening through a long passage which gradually increases in size. There are no sudden expansion points in the flow path which would be likely to result in formation of crystals either in the valve housing or stem.

United States Patent 3,137,416 6/1964 Shepherdetal. 3,257,043 6/1966LeFerre ABSTRACT: An improved aerosol valve intended to prevent cloggingwith salt crystals provides a high velocity turbulent flow through thestem with interior channels gradually increasing in size. The stemorifices break through into a rectangular portion of the stem flowpassage which is the same width as the orifices. The capillaryattraction of residue fluid by the narrowly spaced walls preventclogging of the orifices. The concept further includes a spring cup orvalve housing wherein'the material gradually expands from a restrictedentrance opening through a long passage which gradually increases insize. There are no sudden expansion points in the flow path which wouldbe likely to result in formation of crystals either in the valve housingor stem.

non-ctoccrnc AsRosoL VALVE The invention is an improved aerosol valveassemblywith the general object of avoiding stoppage or clogging at anypoint in the flow system. It provides for a smooth flow from therestricted entrance leading to the valve housing all the way to theactuator, eliminating points of sudden expansion.

It has been found that conventional aerosol constructions are notsuccessful when used with certain types of materials having a highpercentage of metallic salts such as found in antiperspirantpreparations. Much trouble has been experienced especially with cloggingat the valve stem orifices and also, to a lesser extent, bycrystallization in the bottom portion of the spring cup or valvehousing.

My invention avoids such causes of failure by novel shapes andconstruction in the valve stem and valve housing. First, the valve stemprovides a smooth flow from the stem orifices into a gradually expandingstem passage so shaped as to provide high velocity turbulent flow, withthe side walls of the channel near the orifices being shaped and locatedso as to pull away from the stem orifices such residue of material asmay be left in the stem between actuations of the valve. Secondly, thevalve housing has a generally smooth interior wall surface graduallyexpanding along a relatively long flow channel through the dip tubenipple to a port in the bottom wall of the valve housing. Such port isalmost as large as the internal diameter of the bottom portion of thehousing leaving only a narrow shoulder to provide a seat for the springand with the sidewalls of the housing itself being as smooth as possibleand tapering gradually to the area of the valve head.

Various other objects and advantages of the invention will hereinaftermore fully appear.

In the accompanying drawings, l have shown for purposes of illustration,one embodiment which the invention may assume in practice. In thesedrawings:

FIG. I is a perspective in central section showing the improved valveassembly;

FIG. 2 is a vertical cross section with the valve closed;

FIG. 3 is a vertical cross section with the valve open, the valve itselfbeing shown in side elevation;

FIG. 4 is a fragmentary, vertical section of a portion of FIG. 2, but ona larger scale;

FIG. 5 is a vertical cross section through the valve at right angles toFIG. 4;

FIG. 6 shows a portion of the valve in side elevation with a portionbroken away to reveal one of the stem orifices;

FIG. 7 is a top plan view of the valve stem;

FIGS. 8 and 9 are cross sections on lines 8-8 and 9 respectively of FIG.5.

The improved functional features of the present valve are obtained in aconstruction having the advantages of tilt action and possibility offast gassing or filling in accordance with Briechle US. Pat. No.3,158,298. A metal cap 10 has a rolled rim 1] for connection to themouth of a container and a central pedestal 12 having a top wall 13 witha central aperture 14. An annular valve seat 15 also has a central holeI6 registering with the hole 14 in the cap and is positioned against theunderside of the cap wall 13. The valve housing is a onepiece molding ofsuitable plastic material being generally cupshaped with a bottom wall17, a side wall 18 which has a smoothly sloping interior surface 19leading to a thickened cylindrical portion 20. This portion has ribs 21around its periphery communicating with the under surface of the capwall 13 to allow quick filling when the valve seat gasket 15 is pusheddown. The wall of the pedestal portion 12 of the cap is indented asindicated at 22 to secure the valve housing to the cap.

The valve member has a head 23 with a slightly dished upper surface 24so as to allow the corners 25 to seat and seal against the gasket 15 butotherwise avoids the usual well in the top of the valve head. A valvestem 26 projects upwardly from the valve head through the centralopenings in the valve seat gasket l5and the opening 14 of the cap andterminates at its upper end in a hollow cylindrical shape 27. There isalso indicated an actuator button 28 fitted tightly on the cylindricalsurface of the valve stem and having a discharge passage 29. The valvestem is molded with a circumferential groove 30 around the base and thisgroove is of less height than the thickness of the valve seat gasket 15so that the gasket can nevertheless form a seal around the: stem whenthe valve is closed.

As to the flow channel or channels in the stem, there is first therectangular passage 31 leading all the way from the top cylindricalportion 32 through and slightly beyond the groove 30. While thesidewalls of this passage are quite close together, it is wide enough tointersect the groove 30 so as to form two opposed stem orifices 33. Ashort distance above the groove 30, a pair of gradually enlarging sidechannels 34 and 35, having flaring surfaces 36 and 37 near the bottomand flaring surfaces 38 and 39 near the top, which surfaces 38 and 39also widen out to merge with the bore of the cylindrical portion 32.This allows for a high velocity flow especially near the bottom of thestem and avoids any abrupt expansion at any point during the flowthrough the stern. After the valve has been actuated, there will be aslight amount of fluid left in the actuator button 28 and the stem whichmay tend to collect around the stem orifices 32 and 33. Due to the factthat the sidewalls of the rectangular passage 31 are closely spaced andlead directly away from the stern orifices, the residue fluid is pulledaway from those orifices by capillary attraction as indicated by themeniscus curves 40 where the liquid level might settle.

A nipple 41 extends downwardly from the bottom wall 17 of the valvehousing and its outer surface is adapted to receive a dip tube 42. Anentrance opening 43 at the bottom of this nipple 41 is necessarily ofrestricted diametensomething of the order of 0.016 of an inch, so as tometer the flow of fluid. From this orifice, the fluid goes through arelatively long flow passage 44 that gradually expands preferably alongsmooth, slightly curving sidewalls as indicated in the drawings to aport 45 which opens into the valve housing interior. This port is onlyslightly smaller'in diameter than the interior of the housing wall 18 toprovide a narrow shoulder 46 serving as a rest or a seat for a spring47. This spring acts against the underside of the valve head 23 to urgeit against the valve seat 15. The port 45 where the passage 44 opensinto the valve housing is several times as large as the restrictedentrance opening 43 and preferably at least ten times as large in area.The passage 44 is (as shown) at least about twice as: long as thediameter of the port 45. There is, thus, provided an opportunity, forgradual expansion of the fluid under the action of the propellantmaterial so that there is no abrupt change such as might causecrystallization where the material enters the valve housing. The smoothflow concept is carried through the valve housing itself and around thevalve to the stem orifices 32 and 33 and thence into and through thevalve stem itself.

A vapor tap opening is provided preferably as close to the valve aspossible. The one herein shown and indicated by the numeral 48 is simplya hole in a small boss 49 formed on the valve housing. The vapor andliquid are now blended just before leaving the valve housing thusminimizing premature mixing of the vapor and liquid.

lclaim:

1. An aerosol assembly which includes a. a cap to be secured to themouth of a container and having a central opening;

b. an annular valve seat of resilient material positioned against theunderside of said cap in registration with said central opening;

c. a valve having a head adapted to :seat against the underside of saidvalve seat and an integral hollow valve stem projecting upwardly fromthe head through the openings in said valve seat and cap; and

d. a cup-shaped valve housing surrounding said valve, said housinghaving a bottom wall and a reduced diameter nipple extending downwardlytherefrom adapted for connection with a dip tube and having at itsbottom end a restricted fluid entrance opening;

the improvement which consists of a smooth walled flow passage extendingfrom said restricted entrance opening through the length of said nippleand the bottom wall of said valve housing, said passage increasinggradually in size from said entrance opening to a port where it exitsthrough said bottom wall which is more than ten times as large incross-sectional area as said restricted entrance opening, the passagebeing at least about twice as long as the diameter of the port, saidbottom wall presenting a narrow shoulder surrounding said port, theinterior surface of said housing upwardly of said shoulder for the mostpart tapering smoothly to the region of said valve head and a springseated on said shoulder and acting against said valve to urge it againstthe valve seat.

2. Thecombination defined in claim 1, wherein the internal flow passageof said stem adjacent the head is rectangular in cross section withrelatively narrowly spaced side surfaces, one or more stem orificesimmediately above said head which merge smoothly into the sides of saidrectangular interior channel, and a pair of said channels extendingradially outwardly from said side surfaces of the rectangular channelbeginning in a region of the valve stem above such orifice ororificesand having sloping surfaces near their bottom ends and flaringoutwardly near their upper ends to provide smooth expansion to the upperend of the stern where the cross-sectional area is enlarged to severaltimes that of the flow channel at the bottom end of the stem.

3. In an aerosol valve assembly which includes a. a cap adapted to besecured to the mouth ofa container and having a central opening;

b. an annular valve seat of resilient material positioned against theunderside of said cap in registration with said central opening;

projecting upwardly from the head through the openings in said valveseat and cap; and

d. a cup-shaped valve housing surrounding said valve; the improvementwherein said stem has a circumferential groove defining a neck justabove said valve head, a flow passage through said stem, which has arectangular cross section adjacent said head with relatively narrowlyspaced sidewalls which intersect said groove to provide a pair of stemorifices, said flow passage beginning a substantial distance above saidorifices, having side channels shaped to avoid abrupt changes incross-sectional areas of the flow passage, said side channels and saidrectangular channel merging into a cylindrical bore at the top endportion of the stem to provide high velocity turbulent flow with smoothexpansion in the stem area, and wherein the sidewalls of saidrectangular channel serve by capillary attraction of residue fluid, toprevent accumulation at the base of the stem and clogging of the stemorifices.

4. The combination defined in claim 3 wherein the spacing of thesidewalls in the lower portion of said stem flow passage which is ofrectangular cross section is of, the order of one sixty-fourth of aninch.

1. An aerosol assembly which includes a. a cap to be secured to themouth of a container and having a central opening; b. an annular valveseat of resilient material positioned against the underside of said capin registration with said central opening; c. a valve having a headadapted to seat against the underside of said valve seat and an integralhollow valve stem projecting upwardly from the head through the openingsin said valve seat and cap; and d. a cup-shaped valve housingsurrounding said valve, said housing having a bottom wall and a reduceddiameter nipple extending downwardly therefrom adapted for connectionwith a dip tube and having at its bottom end a restricted fluid entranceopening; the improvement which consists of a smooth walled flow passageextending from said restricted entrance opening through the length ofsaid nipple and the bottom wall of said valve housing, said passageincreasing gradually in size from said entrance opening to a port whereit exits through said bottom wall which is more than ten times as largein cross-sectional area as said restricted entrance opening, the passagebeing at least about twice as long as the diameter of the port, saidbottom wall presenting a narrow shoulder surrounding said port, theinterior surface of said housing upwardly of said shoulder for the mostpart tapering smoothly to the region of said valve head and a springseated on said shoulder and acting against said valve to urge it againstthe valve seat.
 2. The combination defined in claim 1, wherein theinternal flow passage of said stem adjacent the head is rectangular incross section with relatively narrowly spaced side surfaces, one or morestem orifices immediately above said head which merge smoothly into thesides of said rectangular interior channel, and a pair of said channelsextending radially outwardly from said side surfaces of the rectangularchannel beginning in a region of the valve stem above such orifice ororifices and having sloping surfaces near their bottom ends and flaringoutwardly near their upper ends to provide smooth expansion to the upperend of the stem where the cross-sectional area is enlarged to severaltimes that of the flow channel at the bottom end of the stem.
 3. In anaerosol valve assembly which includes a. a cap adapted to be secured tothe mouth of a container and having a central opening; b. an annularvalve seat of resilient material positioned against the underside ofsaid cap in registration with said central opening; c. a valve having ahead adapted to seat against the underside of said valve seat and anintegral hollow valve stem projecting upwardly from the head through theopenings in said valve seat and cap; and d. a cup-shaped valve housingsurrounding said valve; the improvement wherein said stem has acircumferential groove defining a neck just above said valve head, aflow passage through said stem, which has a rectangular cross sectionadjacent said head with relatively narrowly spaced sidewalls whichintersect said groove to provide a pair of stem orifices, said flowpAssage beginning a substantial distance above said orifices, havingside channels shaped to avoid abrupt changes in cross-sectional areas ofthe flow passage, said side channels and said rectangular channelmerging into a cylindrical bore at the top end portion of the stem toprovide high velocity turbulent flow with smooth expansion in the stemarea, and wherein the sidewalls of said rectangular channel serve bycapillary attraction of residue fluid, to prevent accumulation at thebase of the stem and clogging of the stem orifices.
 4. The combinationdefined in claim 3 wherein the spacing of the sidewalls in the lowerportion of said stem flow passage which is of rectangular cross sectionis of the order of one sixty-fourth of an inch.